Punch press



L. HERMAN] Oct. 31, 1944.

PUNCH PRESS Filed Feb. 5, 1945 2 Sheets-Sheet l lp aidffe mani wvfi I I awn/M54 Oct. 31,1944. HERMANI 2,361,687

PUNCH PRESS Filed Feb. 5, 1943 r 2 Sheets-Sheet 2 Patented a. 31, 1944 UNITED [STATES ascrea'z PUNCH PRESS Louis Hermani, Baltimore, Md, assignor to Delaware ens-Illinois Can Oompany, a corporation oi Application February 5, 1943, Serial No. 474,774

6 Claims.

An object of the invention is to provide a machine adapted for cutting blanks from a strip or sheet material in a manner to eliminate or reduce to a minimum, the amount of waste material. To this end the machine provides mechanism for cutting blanks which are approximately rectangular in form, with the corners rounded, the blanks being'cut in such a manner that there is no waste material except the small pieces of scrap severed from the rounded corners, and in some instances, a narrow margin at the end of the stock strip.

I Other objects of the invention will appear hereinafter.

Referring to the accompanying-drawings:

Fig. 1 is a fragmentary part-sectional eleva-' tion of a punch press constructed in accordance with the present'invention.

Fig. 2 is a view looking down on the machine in an inclined direction normal to the bed or bolster plate of the machine.

Fig. 3 is a plan view of a. strip from which the blanks are cut.

Fig. 4 is a sectional elevation through the blank cutting punch and die.

Fig. 5 is a,section at right angles to Fig. 4 showing both punches and dies.

Fig. 6 is a perspective view of a die block.

The machine as herein shown, comprises a main frame In of usual construction, having an inclined bed or platform II on which is mounted a bolster plate l2, secured to the bed by means of bolts l3 extending through slots 14 in the bolster plate. A die block I5 is mounted on a platen is which is supported on the bolster plate 42.

The die block I5 is formed with a die opening I8 which cooperates with a press punch IQ for cutting the blanks B from strips 20 of sheet metal or other material.

A pair of shaping dies is arranged in line' with the die l5 and comprises an upper die member 2|, and a lower die 22. The latter is secured by bolts 23 to the bolster l 2. The upper die members ls and 2! are mounted on the lower side of a plate 24 which is secured to and forms part of a head or frame 25 which is periodically moved up and down in guideways 26 on the main frame. The

plate 24 is slidable on guide posts 21 rising'irom the bolster plate l2.

A horizontally disposed arm 23, the inner end of which is supported ona spacing block 29 (Fig. 5 4) on the plate 12, provides a guideway along which the'strips 20 of sheet metal stock are fed to the punch press. Guide strips 30 and 3| are mounted on the arm 23 in position to overlie the margins of the strips 20 as the latter are advanced. The strip 20 is moved forward.intermittently step by step in synchronism with the movements of the punch l9, thereby positioning the forward end of the strip at each step movement over the die opening l8 so that as the punch I9 descends, it cuts a blank B. The strip is arrested. at the end of each step movement and held in such position that its forward edge coincides with the forward edge of the punch so that there is no waste material cut from the side 20 of the blank. The width of the strip 20 and the guideway through which it passes are also substantially equal to the length of the blanks so that no waste material is cut from theends of the blanks. The rounding of the corners of the blanks leaves small corner pieces 32 (Fig. 3)

which are cutaway at the front end of the strip 20 when the first blank is punched. Waste corner pieces 33 in like manner are cut away as each succeeding blank isstamped from the strip, each piece 32 representing comers of two succeeding blanks.

A blowing device is provided for blowing away the waste pieces .32 and 33. It comprises an air pressure pipe 34 connected to a header 35 having 35 branch pipes 33, the forward ends of which connect with channels 31 extending through'blocks 38 which serve'as nozzles from which the air is blown. The nozzle openings, are inclined (as shown) to. direct blasts of air against the waste 40 pieces 32 and 33 as the latter are severed and blow them downward along one of the inclined surfaces 39 formed on the die block.

A hood 40 (Fig. 4) is mounted on the plate 12 and extends over the inclined surface 39, being spaced to provide a passageway through which the waste material is carried. The bolsteris provided with an opening 4| in line with the hood, through which the material is discharged.

The length of the stock strip 20 may be such that when the last blank is cut therefrom, a narrowend strip 42 is left. This strip is discharged through a passageway 43 (Fig. 4) extending along the inclined surface 39 and through the block 29 and pillow block 12. Inorder to insure the strip 42 being completely disconnected from the blank upwardly during the. final punching movement.

When the last blank is punched from a stock strip, the finger 44 strikes any remnant 42 and pushes it downward, thereby starting it through the channel 43,

When a blank B is severed from the strip 20,

it drops down onto the platen l6 (Fig. and

then slides lengthwise rearwardly and downwardly into position between the shaping dies 2| and 22. The bottom face of the die block |5 is cut away at 46 to provide a passageway for the blank. The blank moves between guide strips 46* onto a stripper block 41 and is arrested by a stop 46' The stripper block 41 is mounted for up and down movement in a recess 48 formed in the plate I2. The lower die 22 extends through an opening in the stripper block. Said block is yieldingly held in its lifted position with its upper surface flush with that of the platen M5, by means of a buffer device 50. The latter includes -a body or block 5| of rubber or like elastic compressible material, supported on a disk 52 carried on a rod 53 fixed to and depending from the bolster plate. A pair of rods 54 attached to and depending from the block 41 are connected at their lower ends to a plate 55 overlying the body 5|.

, When ablank B has been positioned over the lower die 22, the upper die 2| descends and shapes the blank as shown (Fig. 5). The particular form of die herein shown is adapted to turn the marginal portion of the blank at right angles to the body thereof for forming a section of a shallow box or receptacle. As the die'2l descends, it engages the block 41 and moves the latter downward during the shaping of the blank, to the Fig. 5 position, thereby compressing the block 5|.

When the die 2| commences its upward movement, the block 5| by its expansive force, lifts the stripper 41 and thereby strips the blank from the lower die member, leaving it in the upper die 2|.

An ejecting device for discharging the finished blank from the upper die comprises an ejector block 56 mounted in the die opening. This block has a headed stem 51 (Fig. 1) on which. is mounted a coil compression spring 58 tending to hold the head 56 in its upper position relative to the die. A rod 59 is movable up and down in a sleeve 60 within an annular member 6| carried on the plate 24. A coil spring 62, mounted on the rod 59, is held under compression and yieldingly holds said rod in its upper position. The rod has an offset end 63 which extends over the rod 51. Means for moving the rod 59 downward relative to the die 2|, comprises a rock arm 64 which is pivoted at'65 to the machine frame. An adjustable' stop screw 66 limits its upward movement. --When the frame 25 carrying the punch-2|, is lifted, the rod 59 is arrested by the arm 64 so that the further upward movement of said frame operates through the rods 59 and 5? to stop the ejector block 56 so that the blank is ejected from the die. The blank is directed into a chute 61 and discharged from the machine.

Modifications may be resorted to within the spirit and scope of the appended claims.

I claim:

1. A punch press machine comprising a punch and die shaped for cutting blanks of substantially rectangular form with rounded corners, from a strip of sheet material, means providing a guideway of such width and so arranged that a strip of said material fed therethrough to the dies may be cut to form a series of blanks with no waste material except the corner pieces severed by the rounded corners of the die.

2. A punch press machine comprising a punch and die shaped for cutting blanks of substantially rectangular form with rounded corners, from a strip of sheet material, means providing a guideway of such width and so arranged that a strip of said material fed therethrough to the dies may be cut to form a series of blanks with no waste material except the corner pieces severed by the rounded corners of the die, means providing a passageway through which said corners are discharged, and a blower arranged to direct blasts of air against said corners as they. are severed.

'3. A machine for cutting blanks comprising a die block having a die opening therein and downwardly and outwardly inclined faces exterior to said opening with their upper edges approximately coinciding with the edges of the said opening, a cooperat ng punch, and means for discharging pieces of waste material down said inclined faces.

4. A machine for cutting blanks comprising a die block having a die opening therein and downwardly and outwardly inclined faces exterior to sad opening with their upper edges approximately coinciding with the edges of the said opening, a cooperating punch, means providing a passageway having one'of said inclined faces formin a wall thereof, and means for directing a blast of air against pieces of waste material cut from said strip and thereby ejecting said pieces through said passageway.

5. A die block formed with a substantially rectangular opening therethrough, said block having a fiat upper surface and having portions cut away to provide downwardly and outwardly inclined surfaces exterior to said opening with the upper edges of said inclined surfaces parallel with and approximately coinciding with opposite cutting edges of the said opening.

6. A blank cutting machine comprising a pair of dies including a stationary die and a movable die, means for feeding a strip of material between the dies, means for reciprocating the movable die and therebycuttng blanks in succession from said strip, a spring actuated finger mounted to reciprocate with said moyable die and contact said strip during the cutting of a blank, said finger being positioned to engage a remnant of the strip during the cutting of the last, blank therefrom, and means providing a passageway through which said remnant is discharged.

LOUIS HERMANI. 

